PROJECT SUMMARY/ABSTRACT Historically, the primary focus of Transfusion Medicine specialists has been the immune compatibility of blood types as well as the safe and appropriate use of blood products. As a consequence of the tremendous growth in the knowledge of blood cell biology, the functions and responsibilities of Transfusion Medicine specialists have expanded to now also include the translation of cell-based therapies. Transfusion Medicine specialists are valued medical and scientific consultants to their colleagues in other disciplines, including among others surgery, cardiology, anesthesiology, neonatology, hematology/oncology. There is a recognized need for scientific training of individuals to further advance knowledge and translation of hematopoietic cellular therapies. The overall goal of the Program in Transfusion Biology and Cellular Therapies is to prepare M.D., M.D./Ph.D. or Ph.D. postdoctoral fellows for biomedical research careers in Transfusion Biology and Cellular Therapy. The program supports 8 postdoctoral fellow slots per year. Funding is provided for 2-3 years after which the fellows are expected to assume positions in academia or in pharmaceutical industry. The program has a broad scope of research activities. The scientific disciplines involved include Immunobiology, Hematopoiesis, and Cellular Therapy. During the first three funding periods, we have developed a multi- disciplinary program utilizing the strong clinical and basic research environments at Harvard Medical School. The major Harvard Medical School affiliated institutions participating in the training program include Boston Children's Hospital, Dana-Farber Cancer Institute, Brigham & Women's Hospital, and Massachusetts General Hospital. Dr. Leslie Silberstein will continue as the Program Director, and Drs. Hongbo (Robert) Luo and Judy Lieberman will continue as Co-Directors. Our approach of including broad representation of faculty is a fundamental strength of our program and fits well with the broad nature of Transfusion Biology and Cellular Therapies and with our overall mission to facilitate cross-fertilization of clinical, basic and translational research talent. The outstanding pool of applicants and recruitment of faculty dedicated to the program has facilitated this goal. Our faculty are not only connected through this postdoctoral training program but also through other Harvard-wide, multi-institutional programs, e.g. Harvard Stem Cell Institute, the TransLab at Boston Children's Hospital and the Dana Farber-Harvard Cancer Center. This Training Program strives to provide a unique and rich training environment for academic transfusion biology and cellular therapies.